Within the field of pressure testing devices, there exists a need for accurate, safe, and reliable connection and testing equipment. Generally, such devices provide connection between two tubings or test fittings. Frequently these fittings are designed to convey pressurized fluids and gases. Often the users of connection and test equipment are exposed to dangerous situations such as high pressure leaks, improper fastening of equipment to high pressure sources, resulting in rapid and unexpected separation of fittings, inaccurate test results, as well as others. Frequently individuals using test fittings, test plugs and the like do not realize the dangers inherent with improper equipment and connections. Moreover, it is often difficult to discern that a test fitting or test plug is improper for the intended use until an undesirable event has occurred. Also, an accurate determination of safe internal pressures prior to attempting a disconnection of pressurized couplings is not generally available in quick connect fittings.
A variety of test equipment and connector couplings have evolved. It should be noted that equipment in the pressure testing field includes equipment which must function with pressurized mediums such as water, refrigerants, oil, and air. The range of equipment therefore includes devices which are generally tested for toughness, reliability, ease of connection, and other important characteristics. Ideally, a test fitting connection device should also provide a safe and positive means for containing various pressures and vacuums of the test medium. It is for the above reasons as well as others that the costs associated with many types of test connections, fittings, and other related equipment are relatively expensive.
The devices of the prior art generally focus on achieving a firm clamp or grip on a test pressure source mechanism and a test pressure destination mechanism by means of a test connector or coupling device. Many such devices provide clamping means for tubing that is attached or inserted within the pressure source and destination mechanisms. The coupling devices connect the pressure source and pressure destination mechanisms to achieve flow-through of a medium for testing or other purposes. Means of attaching the source and destination tubing include: levers or cams which crimp down on the inserted tubing; threaded fittings; pressure activated rams which directly interface with collet type mechanisms; internally inserted engaging pawls; as well as other mechanical connections. In many instances spring biased arrangements are combined with pneumatic and mechanical means to effect seals on test fitting devices such as tubing.
Many prior art devices engage and initially grip the tubing and other test fitting connection means with a mechanical method that crimps or pinches the source or destination tubing. Such crimping, pinching, and other attaching means causes striations, nicks, grooves, and other distortions and damage to the tubing and test connections. This is frequently caused by coupling and testing devices which only allow for close tolerances for various pipe outer diameters. Accordingly, when connected to rough tolerances or varying diameters the excessive crimping and latching onto inserted tubing often results in significant damage to that tubing. Alternatively, inadequate crimping may result in undesired ejection of the tubing from the coupling device.
Some pressure testing devices utilize the pressure of the pressure source to enhance the gripping and sealing of the connections with the pressure destination tubing. This, too, is a problem in the prior art in that increased pressure from a test pressure source may impart excess pinching effect, through various collet and other mechanisms, and result in damage to inserted tubing, test fittings and shortened seal life of coupling device seals. This damage is similar to the problems described above relating to the mechanically derived clamping mechanisms. A problem related to pressure enhanced, that is, unbalanced, couplings is that movement of the inserted test fittings is caused by the force of the pressurized medium acting on a load enhancing piston which forces against the inserted test fittings; the force applied by the load enhancing piston against the test fitting varying in accordance with the pressure of the pressurized medium. This movement then causes gouges and striations to be created on that fitting or tubing by the clamping mechanisms. Similarly, coupling devices in which a tubing is inserted into contact with a movable piston may cause undesirable longitudinal movement of the tubing as pressure is applied to the piston.
Other problems exist in coupling devices which are not internally balanced. That is, in devices which include unbalanced components in pressurized operation, there exists a significant wear and component failure problem. Such problems may create substantial inefficiencies and dangerous operational conditions. Moreover, such devices generally do not provide readily operable means for exhausting or releasing internal pressure prior to disconnection.
Accordingly, there still exists a need to provide a coupling device which includes: a pressure balanced actuator means; means for sealing the coupling device in order to contain a pressurized medium; means for safely and securely gripping pressure source and destination fittings; means for securely attaching and using pressure testing fittings to source and destination pressure fittings without imparting damage to any of the attached components; and means for safely and readily bleeding off pressurized air, or another pressurized medium, which is within the pressure testing fittings prior to disconnecting the coupling device.
What has been further needed has been a pressure testing coupling device which: allows insertion, connection, and pressurized use of test fittings without damage; permits varied tolerances for varied outer diameters of test fittings; is durable and requires low maintenance; provides easy replacement of parts; requires only a minimum level of training to properly operate and maintain; is capable of operating accurately and safely under both high pressure and low pressure conditions; is balanced to reduce the stress on seals and other internal components; and is balanced to provide ease of manual pressure release.
These and other problems are solved by the present invention. Yet other objects and advantages will become apparent from the following descriptions, taken in connection with the accompanying drawings wherein are set forth by way of illustration certain embodiments of the present invention.